Nuprl Lemma : geo-colinear-not-out
∀e:BasicGeometry. ∀a,b,c:Point.  (Colinear(a;b;c) 
⇒ (¬out(a bc) 
⇐⇒ B(bac)))
Proof
Definitions occuring in Statement : 
geo-out: out(p ab)
, 
basic-geometry: BasicGeometry
, 
geo-colinear: Colinear(a;b;c)
, 
geo-between: B(abc)
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
not: ¬A
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
uimplies: b supposing a
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
rev_implies: P 
⇐ Q
, 
false: False
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
not: ¬A
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
stable: Stable{P}
, 
euclidean-plane: EuclideanPlane
, 
basic-geometry: BasicGeometry
, 
or: P ∨ Q
, 
geo-eq: a ≡ b
, 
geo-out: out(p ab)
, 
cand: A c∧ B
, 
basic-geometry-: BasicGeometry-
Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c:Point.    (Colinear(a;b;c)  {}\mRightarrow{}  (\mneg{}out(a  bc)  \mLeftarrow{}{}\mRightarrow{}  B(bac)))
Date html generated:
2020_05_20-AM-09_55_39
Last ObjectModification:
2019_12_23-AM-10_13_59
Theory : euclidean!plane!geometry
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